The protection effect and mechanism of hyperbaric oxygen therapy in rat brain with traumatic injury

Purpose: To investigate the effect of hyperbaric oxygen therapy (HBOT) on traumatic brain injury (TBI) outcome. Methods: The modified Marmarou's weight drop device was used to generate non-lethal moderate TBI rat model, and further developed in vitro astrocytes culturing system. Then, we analyzed the expression changes of interested genes and protein by quantitative PCR and western blot. Results: Multiple HBO treatments significantly reduced the expression of apoptosis promoting genes, such as c-fos, c-jun, Bax and weakened the activation of Caspase-3 in model rats. On the contrary, HBOT alleviated the decrease of anti-apoptosis gene Bcl-2 and promoted the expression of neurotrophic factors (NTFs), such as NGF, BDNF, GDNF and NT-3 in vivo. As a consequent, the neuropathogenesis was remarkably relied with HBOT. Astrocytes from TBI brain or those cultured with 21% O2 density expressed higher NTFs than that of corresponding controls, from sham brain and cultured with 7% O2, respectively. The NTFs expression was the highest in astrocytes form TBI brain and cultured with 21% O2, suggesting a synergistic effect existed between TBI and the following HBO treatment in astrocytes. Conclusion: Our findings provided evidence for the clinical usage of HBO treating brain damages.(AU)

Indirect evidence of predation and intraspecific agression in three sympatric lizard species from a semi-arid area in northeastern Brazil

We analyzed the frequency of tail autotomy, toe amputation and integument scars in three sympatric lizard species, Ameivula ocellifera, Tropidurus hispidus and T. semitaeniatus, from a Neotropical area of semi-arid Caatinga, in northeastern Brazil. We evaluated intraspecific differences in the frequency of injuries between the sexes within each species. Only in A. ocellifera there were differences in frequency of toe amputation and integument scars between males and females, with more injured females than males. This highest frequency of body injuries in females of A. ocellifera might be attributed to the mating behavior of the species, in which males bite and scratch the females. None of the species analyzed presented intersexual differences in frequency of tail autotomy. These findings might be due to similar predation pressure upon males and females as suggested for other lizards species.

Indirect evidence of predation and intraspecific agression in three sympatric lizard species from a semi-arid area in northeastern Brazil

We analyzed the frequency of tail autotomy, toe amputation and integument scars in three sympatric lizard species, Ameivula ocellifera, Tropidurus hispidus and T. semitaeniatus, from a Neotropical area of semi-arid Caatinga, in northeastern Brazil. We evaluated intraspecific differences in the frequency of injuries between the sexes within each species. Only in A. ocellifera there were differences in frequency of toe amputation and integument scars between males and females, with more injured females than males. This highest frequency of body injuries in females of A. ocellifera might be attributed to the mating behavior of the species, in which males bite and scratch the females. None of the species analyzed presented intersexual differences in frequency of tail autotomy. These findings might be due to similar predation pressure upon males and females as suggested for other lizards species.

Indirect evidence of predation and intraspecific agression in three sympatric lizard species from a semi-arid area in northeastern Brazil

We analyzed the frequency of tail autotomy, toe amputation and integument scars in three sympatric lizard species, Ameivula ocellifera, Tropidurus hispidus and T. semitaeniatus, from a Neotropical area of semi-arid Caatinga, in northeastern Brazil. We evaluated intraspecific differences in the frequency of injuries between the sexes within each species. Only in A. ocellifera there were differences in frequency of toe amputation and integument scars between males and females, with more injured females than males. This highest frequency of body injuries in females of A. ocellifera might be attributed to the mating behavior of the species, in which males bite and scratch the females. None of the species analyzed presented intersexual differences in frequency of tail autotomy. These findings might be due to similar predation pressure upon males and females as suggested for other lizards species.

CAPTURA INCIDENTAL DE RAIAS NA PESCA DO CAMARÃO-SETE-BARBAS DO PEREQUÊ, GUARUJÁ, SÃO PAULO, BRASIL

Elasmobrânquios são componentes tróficos importantes em ecossistemas marinhos. Suas estratégias de vida como baixa fecundidade, maturidade sexual tardia e crescimento lento, os tornam altamente vulneráveis às ações antrópicas em zonas costeiras. A comunidade pesqueira do Perequê é tradicional na pesca de arrasto de pequeno porte dirigida ao camarão-setebarbas. Arte de pesca que por ser pouco seletiva, possui alta taxa de capturas incidentais, inclusive de espécies de raias ameaçadas como Rhinobatos horkelii e Zapteryx brevirostris, capturando todos os estádios de maturação sexual. Entre os elasmobrânquios capturados pelos pescadores do Perequê, as raias não possuem valor comercial, sendo descartadas ao mar pelos pescadores, fato importante que facilita ações conservacionistas. A compreensão do estado físico, fisiológico e de sobrevivência dos indivíduos capturados como fauna acompanhante, e a observação das variáveis biológicas e operacionais da captura são fundamentais para o entendimento dos aspectos desse esforço de pesca que podem ser modificados, minimizando os efeitos letais de captura espécie-específicos. Historicamente parâmetros biológicos para estudo de elasmobrânquios têm sido obtidos por amostragem letais dos indivíduos, no entanto, se o objetivo for conservação, é preciso empregar abordagens multidisciplinares para desenvolver métodos alternativos. O presente estudo realizou um levantamento da fauna de raias que ocorrem na pesca de arrasto do camarão-sete-barbas na praia de Perequê, Guarujá, Litoral Centro de São Paulo. Em 83,8% dos arrastos acompanhados ocorreram capturas de raias, sendo estas de nove espécies e de seis famílias. Dos batoides amostrados 48,7% eram indivíduos juvenis (n=56) e 30,4% neonatos, demonstrando a importância da região para a reprodução desses animais. Em relação às injúrias físicas sofridas pelas raias no momento da captura, 59,6% apresentaram pequenas lesões ou nenhuma lesão aparente, 24,5% com lesões moderadas e 16% das raias apresentaram lesões extensas. Se faz de extrema importância ações conjuntas entre a academia e comunidade pesqueira, para a mitigação dos impactos pesqueiros, principalmente em relação às espécies ameaçadas e locais de relevância ecológica para essas espécies. Desta forma, recomenda-se o aperfeiçoamento da metodologia de captura, a prioridade na triagem e soltura imediata de tais animais, assegurando assim a sobrevivência dos indivíduos capturados de forma incidental. Todo o estudo foi realizado com o emprego de métodos não letais.

Elasmobranchs are important trophic components in marine ecosystems. Their life strategies as low fertility, late sexual maturity and slow growth, make them highly vulnerable to human activities in coastal areas. The fishing community in Perequê beach uses a traditional artisanal shrimp fishing trawl. Fishing gear to be somewhat selective, presents a high rate of incidental catches, including endangered species of rays as Rhinobatos horkelii and Zapteryx brevirostris, reaching all sexual maturity stages. Elasmobranch captured by Perequê fishermen, are rays that have no commercial value and are discarded at sea by fishermen, an important fact which facilitates conservation actions. Understanding the physical, physiological and survival condition of individuals captured as bycatch, observing the biological and operational variables capture, is fundamental to the understanding of aspects of fishing gear that can be modified to minimize the lethal effects on species-specific capture. Historically biological parameters for studying the biology of elasmobranch fishes have been obtained by lethal sampling of individuals; however, if the objective is conservation, it is necessary to employ multidisciplinary approaches to develop alternative methods. This study was conducted to characterize the fauna of rays occurring in shrimp trawling in Perequê, Guarujá, Central Coast of São Paulo. In 83.8% of trawls accompanied occurred catch rays, and these nine species and six families. Of batoides sampled 48.7% were juveniles and 30.4% neonates, demonstrating the importance of the region for the reproduction of these animals. In relation to physical injuries suffered by the rays at the time of capture, 59.6% had minor injuries or no apparent injury, 24.5% with moderate injuries and 16% of rays showed extensive lesions. If is very important joint action between academia and fishing community to mitigate the fisheries impacts, especially in relation to threatened species and ecological relevance of sites for these species. Thus, it is recommended to improve the capture methodology, priority in screening and immediate release of such animals, thus ensuring the survival of individuals caught incidentally. All study was conducted with the use of non-lethal methods.

Toxicidade aguda do fipronil em peixes Danio rerio (zebrafish)

No presente trabalho foram investigados os efeitos da concentração subletal de fipronil no comportamento do zebrafish adulto como uma expressão precoce da toxicidade no SNC. Inicialmente foi estabelecida a concentração subletal do fipronil por método de prospecção em 72 horas. Para avaliação comportamental foram observadas a atividade geral, atividade motora, ansiedade, preferência social, preferência sexual e histologia de brânquias dos peixes. Resultados: A concentração subletal obtida foi de 0,5 µg/L. Na atividade geral nas menores concentrações do fipronil aumento na frequência e tempo subida à superfície e nas mais altas, a presença de tremores e movimentos erráticos. A exposição do zebrafish à concentração não letal do fipronil 1) não alterou na atividade motora; 2) promoveu aumento da ansiedade, uma vez que houve redução do número de tentativas de entradas no lado claro e aumento da imobilidade; 3) reduziu a interação social e 4) reduziu a interação sexual;5) promoveu alterações histologia das brânquias. Estes resultados mostram que a exposição por 1 hora à concentração subletal ao fipronil promoveu sinais de toxicidade respiratória e comportamental que poderão interferir com aspectos físicos, sociais e reprodutivos no meio ambiente.

The effects of the sublethal concentration of fipronil on adult zebrafish behavior as an early expression of CNS toxicity were investigated. Initially, the sublethal concentration of fipronil was established by 72 hour prospecting method. For behavioral evaluations the general activity, motor activity, anxiety, social preference, sexual preference were observed. The sublethal concentration obtained was 0.5 g / L. In the general activity, the lower concentrations of fipronil increased the frequency and time raised to the surface and in the higher ones; the presence of tremors and erratic movements were observed at the higher concentrations. Results showed that exposure of zebrafish to non-lethal Fipronil concentration induced; 1) no changes in motor activity; 2) increased in anxiety-like behavior, because is observed a reduction in the number of attempts on the light side and increased immobility; 3) reduced social interaction and 4) sexual interaction; 5) induced injuries in gills. These results show that exposure of zebrafish for 1 hour to the sublethal concentration to fipronil promoted signs of toxicity that could interfere with physical, social and reproductive aspects in the environment.

Avaliação da resposta inflamatória no sistema nervoso central causada pelo herpesvírus equino tipo 1 utilizando um modelo murino de neuroinfecção

O herpesvirus equino tipo 1 (EHV-1) é um importante patógeno que causa doença respiratória, abortamento e desordens neurológicas em equinos. O presente estudo foi realizado visando avaliar a resposta inflamatória causada pelo EHV-1 por meio da análise das manifestações clínicas, alterações histopatológicas e resposta imune do hospedeiro no sistema nervoso central (SNC). Camundongos das linhagens BALB/c (H2d), C57BL/6 (H2b) e C3H/HeJ (H2k) foram inoculados por via intranasal com as estirpes brasileiras A4/72 e A9/92 do EHV-1. Nesse estudo, associou-se a histopatologia, a resposta de citocinas pró-inflamatórias no SNC de camundongos das diferentes linhagens e o método de transcrição reversa seguida pela reação em cadeia da polimerase quantitativa em tempo real (RT-qPCR) para investigar a relação entre a infecção pelo EHV-1 e a resposta inflamatória com o desenvolvimento de lesões. As estirpes brasileiras A4/72 e A9/92 do EHV-1 causaram infecção aguda e letal nas diferentes linhagens de camundongos isogênicos. Os sinais clínicos e neurológicos, tais como perda de peso, pelos arrepiados, postura arqueada, apatia, dispneia, desidratação e sialorreia apareceram entre o 2º e 3º dia pós-infecção (dpi). Essas manifestações foram acompanhadas pelo aumento da sensibilidade a estímulos externos, convulsões, recumbência e morte. As alterações histopatológicas consistiram em necrose neuronal, edema, necrose de liquefação, leptomeningite neutrofílica, manguito perivascular, hemorragia focal, inflamação não supurativa, gliose multifocal e infiltração perivascular de células polimorfonucleares e mononucleares. As características e a extensão das lesões variaram entre as linhagens de camundongos. Animais inoculados com a estirpe A4/72 apresentaram lesões histopatológicas de maior grau de severidade quando comparados com aqueles inoculados com a estirpe A9/92. Observou-se aumento da concentração plasmática de TNF-, IL-6, CCL2 e IFN-g nos camundongos infectados pelo EHV-1 no 2º dpi. Detectou-se aumento da concentração plasmática e da expressão de mRNA para TNF-, IL-6 e CCL2 no SNC dos camundongos infectados pelo EHV-1 no 3º dpi; entretanto, não houve aumento da concentração plasmática nem da expressão de mRNA para IFN-g no 3º dpi. Evidenciou-se que a estirpe A4/72 do EHV-1 induz uma resposta imune sistêmica mais efetiva, enquanto que o vírus A9/92 culmina em uma resposta imunológica mais efetiva no SNC. Os camundongos com o fundo genético C57BL/6 e BALB/c mostraram níveis mais altos de expressão de mRNA para TNF-, IL-6 e CCL2, quando comparados com os C3H/HeJ. A gravidade dos sinais clínicos observados em camundongos infectados pode ser correlacionada com o pico dessas citocinas pró-inflamatórias (TNF- e IL-6) e da quimiocina CCL2, que são produzidas logo após a infecção viral por células residentes da glia e/ou infiltrativas no SNC. Esses achados indicam que as diferentes linhagens de camundongos isogênicos são susceptíveis à infecção por estirpes neuropatogênicas do EHV-1; as diferenças no padrão de alterações histopatológicas mostram que elas dependem do hospedeiro infectado, da estirpe viral e da resposta imunológica; e a supressão do interferon (IFN) tipo 1 sugere ser um mecanismo de escape do EHV-1 frente ao sistema imune. A baixa expressão de IL-6, TNF- e da quimiocina CCL2 em camundongos C3H/HeJ se explica pela mutação no gene toll-like receptor 4 (TLR-4) existente nessa linhagem de camundongo. Adicionalmente, os camundongos C3H/HeJ apresentaram lesões histopatológicas mais severas no SNC quando comparados com BALB/c e C57BL/6. Sugere-se que o IFN tipo I e o gene TLR-4 apresentam importante papel na patogênese do EHV-1 bem como proteínas do agente viral responsáveis pela supressão do IFN e partículas virais que sejam reconhecidas pelo TLR-4 podem ser alvos para o desenvolvimento de novas abordagens para o tratamento da doença viral e para a eficiência de imunógenos.

The equine herpesvirus type 1 (EHV-1) is an important pathogen that causes respiratory disease, abortion and neurological disorders in horses. This study was conducted to evaluate the inflammatory response caused by EHV-1 by the analysis of clinical manifestations, histopathological changes and the host immune response in the central nervous system (CNS). BALB/c (H2d), C57BL/6 (H2b) and C3H/HeJ (H2k) mice were inoculated intranasally with Brazilian EHV-1 strains A4/72 and A9/92. In this study, joined histopathology, the response of proinflammatory cytokines in the CNS of mice of different strains and reverse transcription method followed by quantitative polymerase chain reaction in real time (RT-qPCR) to investigate the relationship between infection by EHV-1 and inflammatory response in the development of lesions. Brazilian strains A4/72 and A9/92 EHV-1 caused acute lethal infection in different strains of inbred mice. Clinical and neurological signs such as weight loss, the bristly hair, hunched posture, apathy, dyspnoea, dehydration and salivary hypersecretion appeared between 2nd and 3rd day after infection (dpi). These events were accompanied by increase in the sensitivity to external stimuli, convulsions, recumbency and death. Histopathological changes were neuronal necrosis, edema, liquefaction necrosis, neutrophilic leptomeningitis, perivascular cuff, focal hemorrhage, non-suppurative inflammation, multifocal gliosis and perivascular infiltration of polymorphonuclear and mononuclear cells. The characteristics and the extent of the injuries varied between strains of mice. Animals inoculated with the A4/72 strain showed histopathological lesions of greater severity when compared with those inoculated with the A9/92 strain. There was an increase in plasma concentrations of TNF-, IL-6, CCL2 and IFN-g in mice infected by EHV-1 in 2nd dpi. Plasma concentrations and the expression of mRNA for TNF-, IL-6 and CCL2 in the CNS of mice infected with EHV-1 at 3rd dpi were increased; however, there was no increase in plasma concentration or expression for the mRNA of IFN-g at 3rd dpi. It was evident that the EHV-1 strain A4/72 induces a more effective systemic immune response, whereas the A9/92 virus culminates in a more effective immune response in the CNS. The C57BL/6 and BALB/c mice showed higher levels of mRNA expression for TNF-, IL-6 and CCL2, compared to C3H/HeJ mice. The severity of clinical signs observed in infected mice can be correlated with the peak of these proinflammatory cytokines (TNF- and IL-6) and CCL2 chemokine, which are then produced after viral infection by resident glial cells and/or infiltrative cells in the CNS. These findings indicate that different strains of inbred mice are susceptible to infection neuropathogenic EHV-1 strains; the differences in the pattern of pathological changes show that they depend on the infected host, the EHV-1 strain and the immune response; and the suppression of interferon (IFN) type I suggested to be an escape mechanism for the EHV-1 against the immune system. The low expression of IL-6, TNF- and chemokine CCL2 in C3H/HeJ mice can be explained by a mutation in toll-like receptor 4 (TLR-4) gene existing in this mouse strain. Additionally, C3H/HeJ mice exhibited more severe histopathological lesions in the CNS as compared to BALB/c and C57BL/6. It is suggested that type I IFN and TLR-4 gene have important role in the pathogenesis of EHV-1 and viral agent proteins responsible for the suppression of IFN and the viral particles that are recognized by TLR-4 can be targets for the development of new approaches for the treatment of viral disease and the efficiency of immunogens.

In vivo effects of Buthus occitanus tunetanus and Androctonus australis garzoni scorpion venoms on pregnant and non-pregnant rats

Scorpion envenomation in pregnant victims has been scarcely studied. Accidents with venomous animals can induce serious injuries for both mothers and embryos. In the current work, the lethality of Buthus occitanus tunetanus (Bot) and Androctonus australis garzoni (Aag) venoms was assessed in pregnant and non-pregnant murine rat models. The median lethal dose (LD50) was determined following the Spearman-Karber method. Our results showed great similarities of envenomation symptoms between term-pregnant and nonmated rats. An unusual vaginal bleeding was also seen in pregnant rats envenomed with Bot and Aag venoms. Our findings suggest that gestation may increase the venoms toxicity in rats.(AU)